采空区自然发火多场耦合数值模拟研究

摘要

采空区遗煤自然发火严重制约着煤矿的安全生产,其受到渗流场、扩散场、化学反应场以及多孔介质传热场共同作用影响,基于这一特点,本文采用有限元数值模拟手段对采空区内部自然发火多场耦合作用进行细致研究,并通过模拟结果与现场实测数据比对验证了模拟的可行性以及模拟结果的可靠性.研究结果表明:依靠传统的三带划分方式并不能很好的确定采空区可能自然发火位置,此外,工作面漏风入口后部煤体温度变化明显,在实际工作中该区域范围应作为重点监控对象.%Coal spontaneous combustion is one of the factors that endangers the produce in coal mine.It is affected by the combined action of seepage and diffusion of gas, chemical reaction of coal and oxygen as well as heat transfer in porous media.Based on this, a series of finite element numerical simulations were conducted to investigate the spontaneous combustion under the effect of different physical field, and the simulation results were compared with the data obtained by in-suit measurement in order to test the accuracy of the simulation data and the feasibility of the simulation model.It is found out that the numerical simulation model acts well in prediction of gas transport and temperature variation, besides it is also discovered that the traditional partition way of the three zone of spontaneous combustion in goaf can not precisely locate the position where spontaneous combustion might occur.In addition, the area behind the entrance of leaked air from working face to the goaf is the place where temperature changes significantly, and it is the most dangerous place that may take place coal fire, so during practical work of coal mining, more attentions should be attached